In the name of efficiency in game programming, some programmers do not trust several C++ features. One of my friends claims to understand how game industry works, and would come up with the following remarks:
- Do not use smart pointers. Nobody in games does.
- Exceptions should not be (and is usually not) used in game programming for memory and speed.
How much of these statements are true? C++ features have been designed keeping efficiency in mind. Is that efficiency not sufficient for game programming? For 97% of game programming?
The C-way-of-thinking still seems to have a good grasp on the game development community. Is this true?
I watched another video of a talk on multi-core programming in GDC 2009. His talk was almost exclusively oriented towards Cell Programming, where DMA transfer is needed before processing (simple pointer access won’t work with the SPE of Cell). He discouraged the use of polymorphism as the pointer has to be “re-based” for DMA transfer. How sad. It is like going back to the square one. I don’t know if there is an elegant solution to program C++ polymorphism on the Cell. The topic of DMA transfer is esoteric and I do not have much background here.
I agree that C++ has also not been very nice to programmers who want a small language to hack with, and not read stacks of books. Templates have also scared the hell out of debugging. Do you agree that C++ is too much feared by the gaming community?
Look, most everything you hear anyone say about efficiency in programming is magical thinking and superstition. Smart pointers do have a performance cost; especially if you’re doing a lot of fancy pointer manipulations in an inner loop, it could make a difference.
Maybe.
But when people say things like that, it’s usually the result of someone who told them long ago that X was true, without anything but intuition behind it. Now, the Cell/polymorphism issue sounds plausible — and I bet it did to the first guy who said it. But I haven’t verified it.
You’ll hear the very same things said about C++ for operating systems: that it is too slow, that it does things you want to do well, badly.
None the less we built OS/400 (from v3r6 forward) entirely in C++, bare-metal on up, and got a code base that was fast, efficient, and small. It took some work; especially working from bare metal, there are some bootstrapping issues, use of placement new, that kind of thing.
C++ can be a problem just because it’s too damn big: I’m rereading Stroustrup’s wristbreaker right now, and it’s pretty intimidating. But I don’t think there’s anything inherent that says you can’t use C++ in an effective way in game programming.